Actually O2 water solubility is much lower then the air we breath and in freshwater 5-8% PPM O2 is where most aquariums fall.
That is the description I was looking for, sorry it was late, I even typo-ed my user name
So for the most part if the fish aren't belly up then the Aerobic bacteria which also live on the bottom of the aquarium, are doing just fine in the canister filter with the O2 soluble water rushing by at 300-600 GPH. In fact due to the concentrated flow of water probubly better then in the aquarium or wet/dry combined.
You would have the same speed water over your wet dry filter only more oxygen available.
Actually my 120 gallon tanks wet dry is running at 650-700 GPH
The anaerobic bacteria will reside in those hard to reach spots deep in the gravel or under some object but they are there. If your gravel is deep in places against the glass sometimes you can see a black blotch in it, not always, usually around a piece of buried food.
My wet dry is very quite and sets right behind my tank so noise is a matter of design not type. (pic below) size is 54" x 4.5" x 20" Media space is 48" x 4" x15" (1.66 cubic feet) won't find that in a canister and mine cost about the same if not less than a canister.
I have seen some VERY noisy canisters.
My experience tells me the bulk of the noise comes from the pump and how well its isolated to vibration. I use RIO pumps since they have ceramic shafts, not sure what others use ceramic but a steel shaft is garbage and will need replacing at some point. My current Rio 250 has right at 10 yrs on it now 24-7-365 and it's as quiet now as it was new.
So sorry but I still see store bought as mostly gimmick but I also see the benifit of just pulling something out of a box and hooking it up,,,, I just prefer to build my own,,,,,,,
and mines better,,,,, Ha Ha
(that's a sarcastic Ha Ha not a cocky one, I'm friendly just opinionated)
